To my understanding (different from what the comments say) here is what I believe being described.
a mattress is float in a pool (not spinning.) The wind is causing them to move in a circular path around the mattress, which leaves ripples in the water in a circle around the mattress.
This book was written in 1925, English has changed a lot since then, and novels usually are also less strict with following exact sentence construction rules. This sentence also sounds confusing to my ears, but also has a melodic feel to it.
To break it down:
this sentence without any modifiers is
The touch revolved it
"touch" in this case is the leaves touch the water. Just as "human touch" refers to the act of a human touching another human. "Revolved" here means that the touch is travelling in a circled around the mattress, not that the mattress is spinning.
With some modifiers:
The touch of a cluster of leaves revolved it slowly
What is describing what is easy to identify with these.
The touch of a cluster of leaves revolved it slowly, tracing a thin red circle in the water.
The phrase added is acting as an adverbial clause describing "revolved", therefore since the touch of a cluster of leaves is the object that is revolving, they are also doing the tracing
After adding the final descriptors
The touch of a cluster of leaves revolved it slowly, tracing, like the leg of compass, a thin red circle in the water
"Like the leg of a compass" is then describing "tracing"
For your first example this sounds fine, but draped is being used as an adjective as opposed to an adverb. If the sentence were "William borrowed the suit, draping neatly on the balcony" the comma makes it sound like "draping" is describing "borrowed". If the comma were deleted there would not be a problem.
For the second example, this doesn't easily make sense, since "whistling to each other" would be describing the how the pushing is done. (also unless its a stream or person named Stream it would need a "the" or an "a."). And the stream is not whistling.
Hope this helps? I think in general a phrase starting with -ing offset by commas is typically adverbial so it describes the verb as opposed to a noun.